Functionality testing of stem cell grafts to predict infectious complications after allogeneic hematopoietic stem cell transplantation.

BACKGROUND AND OBJECTIVES: Allogeneic hematopoietic stem cell transplantation (HSCT) is a routine clinical procedure performed to treat patients with haematological malignancies, primary immune deficiencies or metabolic disorders. Infections during lymphopenia after allogeneic HSCT are associated with high mortality and morbidity. Typical infectious agents are Epstein-Barr virus, cytomegalovirus, herpes simplex virus, varicella-zoster virus and fungi. The study aim was to evaluate whether measurement of the responses of antigen-specific T-cells, recognizing infectious pathogens would correlate to protective functions in the stem cell recipient post-transplant. MATERIALS AND METHODS: Twenty-one grafts were analysed by flow cytometry and cells were stimulated in vitro with relevant infectious antigens, followed by evaluation of T-cell proliferation and cytokine production. Results were compared to the recipients' clinical records 1-year post-transplantation. RESULTS: We show that an extensive repertoire of transferred antigen-specific T-cells from allogeneic donor grafts against infectious agents, involved in post-transplant infections, are linked to an absence of infectious complications for the recipient up-to 1-year post-transplant. The protective effect was associated with antigen-specific T-cell proliferation and IL-1ß secretion. CONCLUSION: Our results suggest that assaying T-cell function before HSCT could determine individual risks for infectious complications and thus aid in clinical decision-making regarding prophylactic and pre-emptive anti-infective therapy.

A prospective randomized toxicity study to compare reduced-intensity and myeloablative conditioning in patients with myeloid leukaemia undergoing allogeneic haematopoietic stem cell transplantation.

BACKGROUND: To our knowledge, no randomized toxicity studies have been conducted to compare myeloablative conditioning (MAC) and reduced-intensity conditioning (RIC) in allogeneic haematopoietic stem cell transplantation (HSCT). METHODS: Adult patients ≤60 years of age with myeloid leukaemia were randomly assigned (1 : 1) to treatment with RIC (n = 18) or MAC (n = 19) in this Phase II single-centre toxicity study. RESULTS: There was a maximum median mucositis grade of 1 in the RIC group compared with 4 in the MAC group (P < 0.001). Haemorrhagic cystitis occurred in eight of the patients in the MAC group and none in the RIC group (P < 0.01). Results of renal and hepatic tests did not differ significantly between the two groups. RIC-treated patients had faster platelet engraftment (P < 0.01) and required fewer erythrocyte and platelet transfusions (P < 0.001) and less total parenteral nutrition (TPN) than those treated with MAC (P < 0.01). Cytomegalovirus (CMV) infection was more common in the MAC group (14/19) than in the RIC group (6/18) (P = 0.02). Donor chimerism was similar in the two groups with regard to CD19 and CD33, but was delayed for CD3 in the RIC group. Five-year transplant-related mortality (TRM) was approximately 11% in both groups, and rates of relapse and survival were not significantly different. Patients in the MAC group with intermediate cytogenetic acute myeloid leukaemia had a 3-year survival of 73%, compared with 90% among those in the RIC group. CONCLUSION: Reduced-intensity conditioning had several advantages compared with MAC, including less mucositis, less haemorrhagic cystitis, faster platelet engraftment, the need for fewer transfusions and less TPN, and fewer CMV infections. Both regimens were tolerated and TRM was low.

Outcome of haematopoietic stem cell transplantation in patients transplanted with matched unrelated donors vs allele-mismatched donors: a single centre study.

We studied the importance of human leucocyte antigen (HLA)-A, -B and -DRB1 high-resolution matching on the outcome of haematopoietic stem cell transplantation (HSCT) with matched unrelated donors (MUDs) vs single allele-mismatched unrelated donors. Fifty consecutive HSCT patients receiving an HLA-A, -B or -DR allele-level-mismatched unrelated graft (mmUD) were compared with a matched cohort of 100 patients with an HLA-A, -B and -DR-MUD. Rejection occurred in seven patients (14%) in the mmUD group and in four patients (4%) in the MUD group (P = 0.04), but this was mainly an effect of HLA-C mismatch. The cumulative incidence of acute graft vs host disease (GVHD) grades II-IV were 61%, 26% and 33% in the class I mmUD, class II mmUD and MUD groups, respectively. In multivariate analysis, HLA class I mismatch was associated with an increased risk of acute GVHD grades II-IV (2.09, P = 0.007) and transplant-related mortality (TRM) (1.99, P = 0.06). The 5-year overall survival was 81% in patients with a class II allele-mismatched donor compared with 52% (P = 0.025) and 50% (P = 0.017) in patients with a class I mismatch and a MUD. In multivariate analysis, HLA class II allele mismatch was associated with improved survival (3.38, P = 0.019). Relapse-free survival were 53%, 37% and 42% in patients with a class II mmUD, class I mmUD and a MUD, respectively (not significant). An HLA-C or -DQ mismatch had no significant impact on survival, TRM and relapse. In conclusion, compared with MUD, HLA class I allele mmUD had an increased risk of acute GVHD and TRM.

Risk factors for acute graft-versus-host disease grades II-IV after reduced intensity conditioning allogeneic stem cell transplantation with unrelated donors: a single centre study.

We analysed factors associated with moderate to severe acute GVHD in 111 patients treated with fludarabin-based reduced intensity conditioning (RIC) and allogeneic haematopoietic stem cell transplantation (HSCT). Most patients had a haematological malignancy. Donors were 97 HLA-A, -B and -DRbeta1 identical unrelated and 14 HLA-A, -B or -DRbeta1 allele mismatched unrelated donors. In the univariate analysis, we found ten factors associated with acute GVHD. These were diagnosis (P=0.06), GVHD prophylaxis with combinations other than CsA+MTX (P=0.006), graft nucleated (P<0.001) and CD34 (P<0.001) cell-dose, bidirectional ABO mismatch (P=0.001), conditioning (P=0.002), hospital vs home-care (P=0.06), ATG dose (P<0.001), donor herpes virus serology (P=0.07) and an immunized female donor to male recipient (P=0.05). In the multivariate analysis, three factors remained significant: a high CD34 cell dose (P<0.001), low dose (4 mg/kg) ATG (P<0.001), and an immunized female donor to male recipient (P<0.01). Patients receiving a CD34 cell dose > or =17.0 x 10(6) per kg had a higher incidence of GVHD, 53.7%, compared to 22.3% in patients receiving a lower dose (P=0.002). In patients without any of these risk factors (n=70), the incidence of acute GVHD was 14.1%, while it was 38.0 and 85.0% in patients with one (n=29) or two (n=10) risk factors (P<0.001). We concluded that risk factors for acute GVHD using RIC are similar as using myeloablative conditioning.

A prospective randomized study using N-acetyl-L-cysteine for early liver toxicity after allogeneic hematopoietic stem cell transplantation.

Allogeneic hematopoietic stem cell transplantation (ASCT) and its conditioning with chemoradiotherapy often results in liver toxicity, the most severe form being veno-occlusive liver disease (VOD). N-acetyl-L-cysteine (NAC), an antioxidant glutathione precursor, may provide protection from liver toxicity. Patients with elevated bilirubin (>26 mmol/l) and/or elevated (ALT) (>1.4 microkat/l) and/or aspartate aminotransferase (AST) (>1.4 microkat/l) levels were randomized to treatment with NAC or no treatment. Among 522 transplanted patients, 160 were included in the trial. NAC was given, 100 mg/kg per day, as a 6-h i.v. infusion until normalization of bilirubin, ALT and AST values. Maximum bilirubin level was the same in patients randomized to NAC (n=72) or controls (n=88). Increase and recovery of ALT and AST were the same in patients randomized to NAC or controls. There were two patients in the NAC group who developed VOD, as compared to three of the controls. To conclude, NAC does not improve liver toxicity after ASCT.

Fludarabine-based disease-specific conditioning or conventional myeloablative conditioning in hematopoietic stem cell transplantation for treatment of non-malignant diseases.

Fludarabine-based conditioning (FBC) was given to 24 patients and conventional myeloablative conditioning (MC) to 33 patients, most children, before hematopoietic stem cell transplantation (HSCT) for non-malignant diseases. The donors were human leukocyte antigen (HLA)-A, -B, -DRbeta1-identical related (33%) or unrelated (67%). In the FBC group, two grafts failed versus three in the MC group; all were successfully regrafted. Fever was more common in the MC patients (P=0.003). Bacteremia occurred in 25% of the FBC group and 50% in the MC group (P=0.1). In the FBC group, platelet engraftment was faster and transfusions were fewer (P<0.05). Mucositis and renal function were similar in the two groups. The MC group had higher maximum bilirubin (P=0.03) and less often normal spirometry (P=0.04) after HSCT. A 7-year-old girl in the MC group had permanent alopecia. No patients had severe acute graft-versus-host disease (GVHD). Chronic GVHD was rare. Complete donor CD3+ chimerism was more common in the MC group (P=0.01), but CD33+ engraftment was better with FBS (P=0.03). Treatment-related mortality was 4 and 15%, and 5-year survival was 89 and 85% in the FBC and MC groups. Although survival was similar, FBC is a promising alternative to MC in non-malignant disorders.

Altered expression of receptors for thyroid hormone and insulin-like growth factor-I during reconstitution after allogeneic hematopoietic stem cell transplantation.

Treatment with neuroendocrine hormones has been suggested to promote reconstitution of the immune system after hematopoietic stem cell transplantation (HSCT). We investigated the expression of genes encoding receptors for growth hormone (GH), insulin-like growth factor-I (IGF-I) and triiodothyronine (T3), at various time points after HSCT in 16 patients and 15 healthy controls. Peripheral blood mononuclear cells were isolated and RNA for GH receptor (GHR), IGF-I receptor (IGF-IR) and thyroid hormone receptor (TRalpha1) was amplified by RT-PCR. The expression of the genes was compared with the expression of beta-actin. We demonstrate increased expression of TRalpha1 RNA in patients at 1.5 months post HSCT, compared to a group of healthy controls, and decreased expression of IGF-IR RNA at 2 and 3 months post HSCT, compared to the controls. Serum from three of the patients was also analyzed for levels of T3, T4, TSH and IGF-I at several time points after HSCT. Serum levels for T3, thyroxine (T4), thyroid stimulating hormone (TSH) and IGF-I were within the normal range in all samples. Our results on the molecular level indicate a role for thyroid hormones and IGF-I in immune reconstitution after HSCT, even though the serum levels of T3, T4, TSH and IGF-I are normal.

Randomized PCR-based therapy and risk factors for invasive fungal infection following reduced-intensity conditioning and hematopoietic SCT.

Invasive fungal infections (IFIs) are major complications after allogeneic hematopoietic SCT (HSCT). PCR-based assays able to detect fungal DNA have been reported to precede clinical diagnosis of IFI. We performed a prospective study to evaluate a PCR-based pre-emptive approach. Ninety-nine patients undergoing reduced-intensity conditioning (RIC) HSCT were followed with fungal PCR during the first 100 days post transplantation. Patients who tested positive were randomized to receive liposomal amphotericin B, or to no intervention. After day 100, PCR tests were performed only on clinical suspicion of IFI. A single positive PCR test was not associated with IFI, irrespective of treatment. After day 100, PCR tests for Aspergillus did not contribute to diagnosis of invasive aspergillosis (IA). The cumulative incidence rates of proven or probable IA during the first year after transplantation were 9%. GVHD grades II-IV (P=0.0014), CMV-seronegative recipient with CMV-seropositive donor (P0.001), and conditioning with alemtuzumab (P=0.014) were significant risk factors for developing IA in a multivariate model. In this study, PCR on peripheral blood was a poor indicator of IFI early after RIC HSCT. Aspergillus PCR tests performed on clinical suspicion after day 100 were insufficiently sensitive to be diagnostically useful.

T-cell receptor Vbeta repertoire after myeloablative and reduced intensity conditioning allogeneic haematopoietic stem cell transplantation.

T cells play an important role in the adaptive immune system. After haematopoietic stem cell transplantation (HSCT), T-cell function is impaired. This is reflected by the emergence of opportunistic infections, infections that are often difficult to treat because of the patient's insufficient immune function. T-cell receptor reconstitution was studied using CDR3 spectratyping to analyze the diversity of the T-cell repertoire at 3, 6 and 12 months after myeloablative and reduced intensity conditioning (RIC) HSCT in 23 patients. Immune function in vitro was tested by lymphocyte stimulation at 3, 6 and 12 months after HSCT. Lower diversity in the CDR3 repertoire was demonstrated in CD4+ cells after RIC HSCT at 3 and 6 months and in CD8+ cells at 3 months compared with healthy donors. After myeloablative HSCT, lower diversity was seen at 3, 6 and 12 months in CD4+ cells and at 6 and 12 months in CD8+ cells after HSCT. Acute and chronic graft-versus-host-disease (GVHD) did not affect diversity. Responses to phytohaemagglutinin (PHA), Concanavalin A (Con A) and Staphylococcus aureus protein A were significantly lower compared with healthy donors during the first 6 months after RIC HSCT. After myeloablative HSCT, lymphocyte response to Con A was significantly lower at 3 months compared with healthy donors. Decreased responses to cytomegalovirus and varicella zoster virus antigens were seen in patients suffering from acute GVHD grade II or chronic GVHD. The T-cell repertoire is skewed under the first year after HSCT, and immune reconstitution after HSCT with myeloablative and RIC conditioning seems to be comparable. GVHD, infections and age are more important for immune reconstitution than type of conditioning.

Reconstitution of the Ig heavy chain CDR3 repertoire after allogeneic haematopoietic stem cell transplantation with myeloablative or reduced-intensity conditioning regimens.

The objective of this study was to investigate B-lymphocyte reconstitution in patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT) after myeloablative conditioning (MAC) or reduced-intensity conditioning (RIC) regimens. B-lymphocyte reconstitution was studied by monitoring the CDR3 repertoire with spectratyping. We demonstrate a delay in the recovery of the B-lymphocyte repertoire, measured by variation in size distribution of the immunoglobulin H CDR3 in patients conditioned with RIC compared to MAC. We found no general explanation for this finding, but when clinical data for each patient were studied in detail, we could identify a cause for the oligoclonality of the B-lymphocyte repertoire after HSCT with RIC for each of the patients. Older patients and donors, low cell dose at transplantation, relapse, graft-versus-host disease (GVHD) and its treatment as well as cytomegalovirus infection and its treatment are all possible causes for the restriction of the B-lymphocyte repertoire observed in this study. Taken together, reconstitution of the B-lymphocyte repertoire after HSCT is a process dependent on multiple factors and differs between patients. The conditioning regimen may be of importance, but data from this study suggest that individual factors and the various complications occurring after HSCT are more likely to determine the development of the B-lymphocyte repertoire.

Memory B lymphocytes determine repertoire oligoclonality early after haematopoietic stem cell transplantation.

The objective of this study was to investigate if oligoclonality of the Ig repertoire post-haematopoietic stem cell transplantation (HSCT) is restricted to memory B lymphocytes or if it is a general property among B lymphocytes. As a measure of B lymphocyte repertoire diversity, we have analysed size distribution of polymerase chain reaction (PCR) amplified Ig H complementarity determining region 3 (CDR3) in naive and memory B lymphocytes isolated from patients before HSCT and at 3, 6 and 12 months after HSCT as well as from healthy controls. We demonstrate a limited variation of the IgH CDR3 repertoire in the memory B lymphocyte population compared to the naive B cell population. This difference was significant at 3 and 6 months post-HSCT. Compared to healthy controls there is a significant restriction of the memory B lymphocyte repertoire at 3 months after HSCT, but not of the naive B lymphocyte repertoire. Twelve months after HSCT, the IgH CDR3 repertoire in both memory and naive B lymphocytes are as diverse as in healthy controls. Thus, our findings suggest a role for memory B cells in the restriction of the oligoclonal B cell repertoire observed early after HSCT, which may be of importance when considering reimmunization of transplanted patients.

Cervical fetal fibronectin correlates to prostaglandin E2-induced cervical ripening and can be identified in cervical tissue.

OBJECTIVE: Our purpose was to investigate whether prostaglandin E2-induced cervical ripening can be related to changes in fetal fibronectin levels and whether fetal fibronectin can be detected by immunohistochemistry in amniotic and cervical tissue. STUDY DESIGN: Fetal fibronectin levels in cervical mucus were quantitated in 28 nulliparous term pregnant women with unfavorable cervical states before and after intracervical application of prostaglandin E2 gel. The concentration of fetal fibronectin was determined with use of an enzyme immunoassay. Cervical biopsy specimens and amniotic tissue for immunohistochemical analysis were obtained from three term pregnant women and after parturition in three women. Cervical biopsy specimens from two nonpregnant women served as controls. Immunohistochemical analysis was performed with antibodies directed toward fetal fibronectin. RESULTS: The fetal fibronectin level in cervical mucus was low in all women before prostaglandin E2 application. In women with a successful prostaglandin E2-induced ripening (i.e., an increase of cervical score with > or =3 points), a tenfold increase in the fetal fibronectin level was registered. In women with an insufficient cervical ripening after prostaglandin E2 treatment no significant increase in the fetal fibronectin level was registered. The immunohistochemical analyses have identified fetal fibronectin in the epithelial cells of the cervix uteri. CONCLUSION: Successful prostaglandin E2-induced cervical ripening seems to be related to a significant increase in cervical fetal fibronectin levels. Fetal fibronectin can be detected immunohistochemically in the pregnant human cervix.

Poor immune reconstitution after four or five major HLA antigens mismatched T cell-depleted allogeneic and autologous stem cell transplantation.

Two adults with primary liver cancer underwent liver transplantation from 5/6 and 4/6 major HLA-antigen mismatched unrelated donors. They were then conditioned with 4 x 2 Gy of total lymphoid irradiation, 120 mg/kg cyclophosphamide, 7.5 Gy total body irradiation and anti-T cell antibodies. Thereafter, the patients received T cell-depleted autologous: unrelated mismatched bone marrow in a proportion of 0.5:3.0 and 0.35:1.1 x 10(6) CD34+ cells/kg, respectively. After allogeneic stem cell transplantation (ASCT), both became mixed chimeras, as determined with polymerase chain reaction amplification of variable number tandem repeats from DNA obtained from CD3+, CD19+ and CD45+ magnetic bead-separated cells. Due to a reduction in donor T cells, the first patient was given 10(5) donor T cells/kg and became a complete donor chimera within 3 months. The second patient rejected all donor cells within 1 month after ASCT. Leucocytes normalized in both patients within 1 month. CD8+ cells normalized after 4 and 2 months in the two patients, respectively. However, CD4+, CD56+ and CD19+ cells remained low, except for a transient increase in patient 2. Lymphocyte responses to mitogens were negative in patient 1 from 1 to 5 months after ASCT. This patient also showed an oligoclonal pattern of the B cell repertoire, performed by CDR3 spectratyping. Epstein-Barr virus DNA in lymphocytes increased by 4-5 log in both patients. Prior to ASCT, recipients and donors were mutually reactive in mixed lymphocyte cultures (MLC). In the first patient, who became a complete donor chimera, the chimera cells showed no response to recipient or donor, but a positive response to third party. In the other patient, recipient cells reacted vigorously against donor lymphocytes at the time of rejection. Both patients suffered from overwhelming bacterial, fungal and viral infections, and died of pneumonia 5 and 3 months after ASCT, respectively. To conclude, with a major HLA-mismatch barrier, stable mixed chimerism seems difficult to achieve. The first patient became a full donor chimera and the second one rejected the graft. Both suffered from immune incompetence.